Field of the Invention
The present invention relates to an ink jet recording method and an ink jet recording apparatus.
Description of the Related Art
An ink jet recording method enables recording of images on various recording media. In order to produce better images, various inks such as inks suited for recording photographic quality images on glossy paper and the like and inks suited for recording documents on plain paper and the like, have been developed according to purposes.
In recent years, the ink jet recording method is also used, for example, for recording business documents containing characters, diagrams, and the like on plain paper or similar recording media, and has been markedly frequently used for such purposes. As the technique of the ink jet recording method develops, ink jet recording apparatuses are required to have higher durability and reliability in order to be usable for a long period of time and also to enable recording of a larger number of images, thereby achieving high productivity. To meet such a demand, an ink jet ink having a high surface tension and a small dissolved oxygen amount is disclosed, for example. This ink is sucked from ejection orifices on a recording head to suppress ejection failure, or what is called a higher purge restoration performance is improved (Japanese Patent Application Laid-Open No. 2004-083621).
In order to improve the productivity, the inventors of the present invention have studied an ink jet recording apparatus that includes a main tank and a sub tank as the ink storage portions to increase the amount of an ink stored. The inventors consequently have ascertained that the reliability is likely to be improved when the ink disclosed in Japanese Patent Application Laid-Open No. 2004-083621 having a small dissolved oxygen amount is used. However, when the above-mentioned ink jet recording apparatus is used to eject inks over a long period of time, another problem is caused. In other words, it is revealed that disorder is likely to be gradually caused on images even when the ink having a small dissolved oxygen amount is used. It has also been ascertained that when the above-mentioned ink jet recording apparatus is used over a long period of time, a color tone change of gray line images recorded by overlapping of a cyan ink, a magenta ink, and a yellow ink is likely to be caused.
An object of the present invention is thus to solve the problems caused when an ink jet recording apparatus including a main tank and a sub tank as the ink storage portions is used over a long period of time. In other words, the present invention aims to provide an ink jet recording method that enables the above-mentioned ink jet recording apparatus to maintain good ink ejection stability even when the ink jet recording apparatus is used over a long period of time and to record images for which a color tone change is suppressed. The present invention also aims to provide an ink jet recording apparatus used in the ink jet recording method.